Combo Box

[saloio]

Hello all

I'm trying to do a triple combo box with descriptions and found this code below on internet:
I'm trying to learn javascript.. but I don't know much. I couldn't change this javascript to 3 combo boxes. I'm trying to make boxes with Maker, Car Model and Year. If possible, when the user hit GO, to the show the description into a div, and do not go to a website.

<form name="doublecombo">
<select name="example" size="1" onChange="redirect(this.options.selectedIndex); displaydesc()">
<option>SimplytheBest Shareware</option>
<option>SimplytheBest Affiliates</option>
<option>SimplytheBest Metasearch</option>
</select>
<select name="stage2" size="1" onchange="displaydesc()">
<option value="http://simplythebest.net/shareware.html">Index</option>
<option value="http://simplythebest.net/business.html">Business</option>
<option value="http://simplythebest.net/graphics.html">Graphics</option>
</select>
<input type="button" name="test" value="Go!"
onClick="go()">
<br />
<input type="text" name="txtdisplay">
</form>
<script>
<!--// Orignal Scripts:
////// Double Combo Script By Website Abstraction (www.wsabstract.com)
////// Drop down menu w/ description by Dynamic Drive (www.dynamicdrive.com)

var groups=document.doublecombo.example.options.length
var group=new Array(groups)
var descr=new Array(groups)
for (i=0; i<groups; i++){
group[i]=new Array()
descr[i]=new Array()
}

group[0][0]= new Option("Index","http://simplythebest.net/shareware.html")
descr[0][0]= "Index description";
group[0][1]= new Option("Business","http://simplythebest.net/business.html")
descr[0][1]= "Business description";
group[0][2]= new Option("Graphics","http://simplythebest.net/graphics.html")
descr[0][2]= "Graphics description";

group[1][0]=new Option("Art and Photo","http://www.simplythebest.net/affiliates/affiliate_programs/art_photo.html")
descr[1][0]= "Art and Photo description";
group[1][1]=new Option("Books","http://www.simplythebest.net/affiliates/affiliate_programs/books.html")
descr[1][1]= "Books description";
group[1][2]=new Option("Clothing","http://www.simplythebest.net/affiliates/affiliate_programs/clothing.html")
descr[1][2]= "Clothing description";

group[2][0]=new Option("Web Search","http://www.simplythebest.net/search/search.html")
descr[2][0]= "Web Search description";
group[2][1]=new Option("Auctions Search","http://www.simplythebest.net/search/auctions.html")
descr[2][1]= "Auctions Search description";
group[2][2]=new Option("MP3 Search","http://www.simplythebest.net/search/mp3search.html")
descr[2][2]= "MP3 Search description";
group[2][3]=new Option("Job Search","http://www.simplythebest.net/search/jobs.html")
descr[2][3]= "Job Search description";

var temp=document.doublecombo.stage2

function redirect(x){
for (m=temp.options.length-1;m>0;m--)
temp.options[m]=null
for (i=0;i<group[x].length;i++){
temp.options[i]=new Option(group[x][i].text,group[x][i].value)
}
temp.options[0].selected=true
}

function go(){
location=temp.options[temp.selectedIndex].value
}

function displaydesc(){
var desc=descr[document.doublecombo.example.selectedIndex][document.doublecombo.stage2.selectedIndex];
document.doublecombo.txtdisplay.value=desc;
}

displaydesc()
//-->
</script>

Thanks!